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Analysis of an Electronic Voting System

Analysis of an Electronic Voting System. TADAYOSHI KOHNO ADAM STUBBLEFIELD† AVIEL D. RUBIN‡ DAN S. WALLACH§ February 27, 2004 Presented by: Aldo Villanueva. Outline. Palm Beach Fiasco Introducing DRE History of Diebold Vulnerabilities of Diebold DRE Summary.

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Analysis of an Electronic Voting System

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  1. Analysis of an Electronic Voting System TADAYOSHI KOHNO ADAM STUBBLEFIELD† AVIEL D. RUBIN‡ DAN S. WALLACH§ February 27, 2004 Presented by: Aldo Villanueva

  2. Outline Palm Beach Fiasco Introducing DRE History of Diebold Vulnerabilities of Diebold DRE Summary

  3. Palm Beach Ballot Fiasco

  4. Palm Beach Ballot Fiasco

  5. DRE “Direct Recording Electronic” • Eliminate paper ballots from the voting process. • Process: • The voter arrives to the voting place and prove he’s allowed to vote there. • He gets a token (PIN or smartcard). • Enters the token in the voting terminal and votes for its candidate. • DRE System presents the voter’s election and gives a final chance to make changes.

  6. History • 1995: I-Mark Systems • 1997: Global Election Systems acquired I-Mark • 2002: Diebold acquired GES and change the name to DieboldElectionSystem • 2006: Diebold removed its name from the voting machines for “strategic” reasons • 2007: Diebold changed its name to "Premier Election Solutions"

  7. Analysis of the Diebold’s AccuVote-TS DRE voting system The source code for Diebold’s AccuVote-TS DRE voting system was analyzed. There were several vulnerabilities found.

  8. Vulnerability No. 1: Smartcards • The smartcards used in the voting process are very easy to fake since they don’t perform any cryptographic operations. • Attacker could: • Cast multiple votes • End the elections early

  9. Vulnerability No. 2: Tampering System configuration : impersonating any other voting terminal. Ballot definitions: changing the order of the candidates only in the interface Election results: modifying the voting records file stored on the device

  10. Vulnerability No. 3: Impersonating legitimate voting terminals Voting terminals are configured to upload voting totals to a system after an election. An adversary able to pose as a legitimate voting terminal to the tabulating authority could report false vote counts.

  11. Vulnerability No. 4: Key management If an attacker with access to the source code learns the key, he can read and modify voting and auditing records. In the Diebold system, from the CVS logs, we see this particular key has been used without change since December 1998.

  12. Vulnerability No. 5: Linking voters to their votes Each vote is written sequentiallyto the file recording the votes. It’s easy for the attacker (poll worker) to access the voting records, to link voters with their votes.

  13. Vulnerability No. 6: Audit logs The whole audit log is encrypted using an insecure method. At the time that the logging occurs, the log can also be printed to an attached printer. An attacker could create discrepancies between the printed log and the log stored on the terminal by unplugging the printer (or, by simply cutting the cable).

  14. Other vulnerabilities • An attacker can delay the start of an election: • DoS attack against the election management’s server preventing the voting terminals from acquiring their ballot definition in time. • Poor software engineering: • Uses C++ • No documentation  Top-to-bottom code review would be nearly impossible.

  15. Summary • Significant security flaws: • Voters can trivially cast multiple ballots • Administrative functions can be performed by regular voters • Threats posed by insiders such as poll workers, software developers, etc.

  16. SECURITY ANALYSIS OF THE DIEBOLD ACCUVOTE – TS VOTING MACHINE Ariel J. Feldman J. Alex Halderman Edward W. Felten September 13, 2006 Presented by: Jiseong Noh

  17. Outline Overview of Diebold AccuVote-TS Voting Machine Design Points Boot Processes Vulnerability Points Attack Scenarios Mitigation of the vulnerabilities Conclusion

  18. Diebold AccuVote-TS • (*)http://www.electiondataservices.com/images/File/NR_VoteEquip_Nov-2008wAppendix2.pdf) • Manufactured by Diebold Election Systems • Sold to Election Systems & Software in 2009 • DRE – Direct Recording Electronic Voting Machine • Voters use machine to cast vote • Machine is used to record the votes • (*) 32% of the USA registered voters used DRE in 2008 • About 16 Million voters used Accuvote-TS in 2010 • Custom election software runs on top of Windows CE

  19. Design Points Serial port Processor RAM Touch Screen SmartCardReader Audio jack RemovableFlash Printer On-boardFlash EPROM Open to Public Key Access Inside Box http://web.cecs.pdx.edu/~hook/cs491sp08/AccessControlSp08.pdf

  20. (CPU) (RAM) Design Points (Flash) • Similar to a general-purpose hand-held PC • A CPU, 32MB RAM, 16MB internal flash storage • Touchscreen LCD display • Two PC card slots – one for memory card, other for modem card • OS uses a customized software • Automatically runs Voting Program • Searches for special files in memory card to administer or update the system • Searches for script files with user confirmation

  21. Boot Process • Boot loader loads itself into RAM • Boot Location determined by jumpers on the board • Onboard Flash Memory (default) • EPROM • Ext Flash slot • Boot loader looks for special file names • fboot.nb0: replacement boot loader • nk.bin: replacement of operating system • EraseFFX.bsq: erases file system on-board flash *** Does not verify file authenticity!

  22. Boot Process • Windows CE image loads and start • Customized task manager • Automatically runs Voting program • If memory card is present and contains explorer.glb • Runs windows explorer instead of voting program • runs script files (. with user confirmation

  23. Vulnerability Points (H/W) Easy Access to Memory Card Lightweight Lock: easily picked up without a key

  24. Vulnerability Points (H/W) EPROM(E): Replace EPROM with malware PC Card Slot(S): Used to replace existing software with malware using Memory Card Serial Keypad Connector(O): open communication port Infrared Port(N): open communication port

  25. Vulnerability Points (S/W) http://www.cyberdin.com/images/stories/pict5.jpg • Authenticity problem • Never checks to validate the authenticity of files on the memory card on booting or updating software • Buffer Overflow • malformed script files could bypass the confirmation

  26. Attack Types • Stealing Votes • Malicious processes runs in parallel with voting program • Change votes for a favored candidate • Total count of votes does not change • Denial-of-Service • Destroys all records of the election • Makes the voting machine inoperable

  27. Delivery of Malicious Code • EPROM • Attack code is placed on an EPROM chip • Attacker replaces the EPROM chip and changes the jumper settings to boot from EPROM • Memory card on PC Card Slot • Attack code is placed on the memory card • Memory card is inserted before voting machine booted • Malicious boot loader containing virus is installed on the machine • The machine is now infected

  28. Delivery of Malicious Code Memory card on PC Card Slot (continue)

  29. Mitigation of Vulnerabilities • Modifications to DRE Software and Hardware • Digitally sign all software updates • Verify the signature of software updates before installing them • Ask user confirmation of any software updates • Use specialized hardware to maintain tamper-proof logs • Physical Access Controls • Sealing the machine and memory card with tamper-evident seals

  30. Summary • DREs are like desktop PC, in the security point of view • Diebold AccuVote-TS has many serious vulnerabilities • Weak physical security • Runs on general-purpose H/W and OS • No way to check if an attack occurred • Virus attack possible – no need for distributed attack • DREs have their advantages; however, they should overcome these problems to make reliable votes

  31. Bankruptcy of Diebold Papers which criticize DRE, particularly Diebold Systems 2003: Analysis of an Electronic Voting System 2004: Trusted Agent Report Diebold AccuVote-TS Voting System 2006: Security Analysis Of The Diebold AccuVote - TS Voting Machine Bad Reputation  Changed the name multiple times May 19, 2010 Dominion Voting Systems acquired Premier Elections Solutions.

  32. Conclusions Voting equipment vendors say closed-source nature of the systems makes them more secure. Authors think that an open process would result better. The best solution will be a computerized voting system with ballot paper.

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